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Biomedical subjects

T Muto

Publications and source records attributed to T Muto.

At least 379 records · Page 21Linked to original sources
PubMed1994

Induction of ovulation by endothelin-3 in rats.

Endothelins vary in their biological activity. We therefore examined the effects of endothelin-3 (ET-3) on ovulation and secretion of LH, FSH and prolactin in rats in which naturally occurring ovulation was blocked by the administration of sodium pentobarbital (40 mg/kg, i.p.) prior to the critical period (1330 h) on the day of pro-oestrus. ET-3 (10 nmol/kg) was given via the jugular vein under pentobarbital anaesthesia from 1600 to 1800 h on the day of pro-oestrous and induced ovulation in all rats whether given by venous injection or by infusion but the number of ova in rats injected with ET-3 was less than that in normally cycling control rats. Infusion of ET-3 stimulated the secretion of LH but caused a lower than expected rate of secretion of FSH. It would therefore appear that ET-3 causes release of the total amount of LH that is required for induction of ovulation. Our findings strongly suggest that ET-3 has a physiologically significant role in the regulation of anterior pituitary hormone secretion.

Animals↗
PubMed1994

[The heterogeneity of periodic acid-thionin schiff/KOH/PAS staining property and the histological grading of atypia in colorectal carcinoma and adenoma].

To assess the mucin changes associated with the development of colorectal cancer, the periodic acid-thionin schiff (PAT)/KOH/PAS staining properties of 38 advanced carcinomas, 8 submucosal invasive carcinoma, 29 mucosal carcinomas (adenomas with severe atypia), 19 adenomas with moderate atypia and 38 adenomas with mild atypia were studied with special attention to the heterogeneity of staining property within each lesion. 6 submucosal carcinomas and 28 mucosal carcinomas were judged to have benign adenomatous portion using hematoxilin-eosin staining. The more advanced the carcinomas, or the higher the grade of atypia of adenomas, the fewer the lesions of which goblet cell mucus (GCM) and the mucus at the luminal surface or that in the luminal accumulation (SC) stained red. SC frequently stained bluer than GCM in highly atypical glands. The staining properties of benign adenomatous portions concomitant with submucosal or mucosal carcinomas were similar to those of benign adenomas, but not to their carcinomatous foci. These findings suggest that the changes in the PAT/KOH/PAS staining property associated with the development of colorectal carcinoma mainly occur in SC, and that the majority of submucosal and mucosal carcinomas were 'carcinoma in adenoma'.

Adenoma↗
PubMed1994

[Organ failure due to hypoxemia, and effects of oxygen therapy--effects of hypoxemia on pulmonary hemodynamics, and improvement with oxygenation].

To investigate pulmonary hemodynamics in patients with chronic respiratory failure, we performed right heart catheterization and also examined the effects of oxygen inhalation. Thirty-three patients were studied. Their mean age was 65 +/- 10 years, and FEV1.0% and PaO2 on room air were 47 +/- 16% and 63 +/- 14 mmHg, respectively. mPAP was 27 +/- 10 mmHg, and 26 (78%) had pulmonary hypertension. Although PVR was abnormally high, CI and PCWP were within normal limits. PaO2 was significant Significantly correlated with mPAP and PVR. Although oxygen inhalation (28%) for 30 minutes significantly changed PaO2, PaCO2, and PvO2, it did not significantly affect mPAP, PVR, CI, or PCWP. These results suggest that short-term oxygen inhalation does not affect pulmonary hemodynamics in patients with chronic respiratory failure. Radionuclid ventriculography was also done to evaluate cardiac function in 16 patients before and after home oxygen therapy (HOT). Both right ventricular ejection fraction (RVEP) and left ventricular ejection fraction (LVEF) were significantly increased by HOT, and the significant correlation between RVEF and LVEF that had been observed before HOT disappeared. These results suggest cardiac function improved and that the interdependence between the right and left ventricle was eliminated by HOT.

Aged↗
PubMed1994

Simultaneous measurement of alcohols and hydrogen cyanide in biological specimens using headspace gas chromatography.

We attempted to analyze biological specimens simultaneously for alcohols and hydrogen cyanide. A headspace gas chromatographic method with thick film wide bore column (PEG 20M) for the simultaneous determinations of methanol, ethanol, n-propanol and hydrogen cyanide in blood has been developed. This method was applied for the determinations of methanol, ethanol and hydrogen cyanide in a forensic autopsy case and animal experiments.

1-Propanol↗
PubMed1994

[Detection of methicillin-resistant Staphylococcus aureus using PCR and non-radioactive DNA probes: IV. Mutational sequences in the region upstream of the mec A gene in clinical staphylococcal strains].

Expression of mec A is regulated by two regulatory genes (mecR1 and mecI); the intact regulatory genes exist in the N315 strain of methicillin-sensitive S. aureus, whereas the repressor gene (mecI) is deleted in the MR108 strain of methicillin-resistant S. aureus (MRSA). However, our previous findings that clinical strains of N315 type were methicillin-resistant suggest possible mutations within the operator region, by which the inhibitory effect of MecI is released to induce the constitutive expression of mec A. Therefore, we analyzed nucleotide sequences in the region upstream of the mec A gene and in the regulatory genes, by using PCR-direct sequencing and ASO probes. Analysis of selected clinical strains by ASO probes revealed that 74% of MRSA and 36% of MRSE (methicillin-resistant S. epidermidis) lacked the mecI gene whereas 26% of MRSA and 64% of MRSE possessed the intact regulatory genes. Furthermore, PCR-direct sequencing identified four different mutations in the operator nucleotide sequence and one mutation in Shine-Dalgarno sequence. Additionally, these mutations were shown to occur in the strains of N315 type with higher probability rather than in those of MR108 type. The data suggest that one or more of these mutational sequences at least may have some influence on the expression of methicillin-resistance in clinical staphylococcal strains.

Base Sequence↗
PubMed1994

The association between extrahepatic biliary carcinoma and the junction of the cystic duct and the biliary tree.

OBJECTIVE: To establish accurately the sites of primary extrahepatic biliary carcinomas, so that optimal treatment may be given. DESIGN: Retrospective study. SETTING: University department of surgery. SUBJECTS: 120 patients with 121 primary extrahepatic biliary carcinomas. MAIN OUTCOME MEASURES: Site of tumour (primary site being geometric centre of tumour) and distance from junction of cystic duct and the biliary tree on histological examination of the resected specimen. RESULTS: 64 of the tumours (53%) were within 5 mm of the junction; 14 were proximal to the junction, 32 distal, and 18 within the cystic duct itself. CONCLUSIONS: Over half the primary extrahepatic biliary tumours were within 5 mm of the junction of the cystic duct and the rest of the biliary tree. Further investigations are required to find out if any particular aetiological factor can be identified.

Adenocarcinoma↗
PubMed1993

Orally administered prostaglandin E1 derivative can enhance liver regeneration in partially hepatectomized rats.

The effect of orally administered 17(S),20-dimethyl-6-oxo prostaglandin E1 (PGE1) methyl ester (OP) on liver regeneration was examined in 66% hepatectomized rats. Administration of OP increased the mitotic index of the hepatocyte 3 days after hepatectomy, and the mitotic index response due to OP was dose dependent. The OP administration had no effect on food intake, but reduced water intake. The serum scores relative to nutrition and hepatic function showed transient change after OP administration, whereas the serum blood urea nitrogen level indicated a slight renal dysfunction with OP. The fat store in the body was transiently reduced. These observations lead us to conclude that orally administered OP is capable of stimulating liver regeneration without serious systemic effects.

Administration, Oral↗
PubMed1993

Transendothelial migration activity of lymphokine-activated killer (LAK) cells.

With an in vitro static system using HUVEC (human umbilical vein-derived endothelial cells) cultured on type I collagen gel, we investigated the transendothelial migration activities of I1-2 activated killer (LAK) cells. Our results indicate that in comparison with unstimulated T cells, LAK cells exhibit strong transendothelial migration activity, as well as increased adhesiveness to HUVEC. Pretreatment of HUVEC for 24 h with rINF-gamma, rTNF-alpha and rIL-1 beta enhanced the LAK cell migration. The increase in the percentage of migration of LAK cells was greater than that of the percentage of adhesion but significantly less than the increase in the percentage of migration of resting T cells. The results of blocking studies using mAb strongly suggest that the enhanced migration of LAK cell was probably attributed to nonspecifically increased binding to HUVEC and markedly enhanced chemokinetic activity that was dependent primarily on the LFA-1 molecule. Among LAK cells, there were considerable differences in the migration activities of the various phenotypes. CD8+T-LAK migrated preferentially to CD4+T-LAK. CD16+ NK-LAK showed increased adhesion but somewhat decreased migration activities. However, rINF-gamma treatment of HUVEC for 24 h promoted vigorous migration of CD16+ NK-LAK, which suggests that endothelium regulate the migration of LAK cells. Based on these observations, we proposed that LAK cells, if transferred into tumor feeding vessels, can migrate into tumor tissue in considerable numbers and efficiently make contact with individual tumor cells to produce preferable clinical effects.

Cell Adhesion↗
PubMed1993

Resting energy expenditure in patients undergoing transhiatal or transthoracic oesophagectomy for carcinoma of the thoracic oesophagus.

Resting energy expenditure (REE) was studied in five patients undergoing transhiatal and in 14 undergoing transthoracic oesophagectomy for carcinoma. All resections were performed with an intention to cure. REE was measured by indirect calorimetry before operation and on days 1, 3, 5 and 7 after surgery. Following transthoracic oesophagectomy, REE increased significantly on days 1, 3, 5 and 7 after operation, and on day 7 the value was significantly higher (P < 0.05) than that obtained after transhiatal surgery. Energy expenditure following transhiatal oesophagectomy is lower than that after transthoracic oesophagectomy; this may be a result of reduced surgical stress.

Adult↗